I applied through university. The process took 4 months. I interviewed at LyondellBasell (Houston, TX) in Nov 2015
Interview
I met a few engineers at my university's career fair. I was selected for an interview at my university. The interview at my university was fairly easy, just ask a few questions from my resume. After a week or so I got a call from the recruiter that I was selected for an on site interview in Houston. The interview at Houston was a little tough. They asked me questions about my resume, safety precaution question, 5 star questions, and also they asked couple of questions to see how I handle conflicts. There were in total of 3 interviews, 2 people interviewing each time.
Phone interview followed up by full day of interviews on-site. I ended up getting a mix of questions about my technical competency as well as motivational fir for the company.